Mast raising and extending mechanism



y 1962 A. H. WILKINSON ETAL 3,032,147

MAST RAISING AND EXTENDING MECHANISM Filed Jan. 28, 1959 FIG. l [*1 l6 r78 INVENTORS ,ALVIN H. WILKINSON BILLY D. PENDERGRAFT BY KENWAY, JENNEY,W1TTER & HiLDRETH ATTORNEYS United rates This invention relates to mast servicing units usually mounted on trucks equipped with winch servicing mechanism and commonly used in oil fields for well servicing and like operations. The mast is ordinarily transported in horizontal position on the truck and is raised to vertical position when use of the mast is required. Mechanism for thus raising and lowering the mast is carried by the truck and the primary object of our invention herein resides in the production of improved and simplified mechanism for performing this function.

The mast usually embodies two or more teles'coped sections and means is ordinarily carried by the truck for telescopically raising and lowering these sections to the positions required. A further feature of the invention resides in the provision of a single winch for conveniently performing this function and also the mast raising and lowering functions.

These and other features of our invention will be more readily understood and appreciated from the following detailed description of a preferred embodiment thereof, selected for purposes of illustration and shown in the accompanying drawing in which FIG. 1 is a side elevation of a mast carrying servicing truck equipped with an embodiment of our invention for raising and lowering the mast and extending it telescopically,

FIG. 2 is an enlarged fragmentary elevation of the mast servicing mechanism shown in FIG. 1.

FIG. 3 is an enlarged sectional view taken on line 3-3 of FIG. 2, and

FIG. 4 is a fragmentary rear end elevation of the truck and mast servicing mechanism.

In the drawing indicates a heavy duty truck mounted on wheels 12 and carrying a servicing unit 14, and a mast 15. The mast comprises a tubular outer base portion 15 having a smaller portion 16 telescoped thereinto and carrying a sheave 18 on its top end. For transportation purposes the mast is supported in horizontal position on the truck as illustrated in FIG. 1. The top end of the telescoped mast is supported on a post 20 carried by the truck and the rear end is suported on a frame 22 rigidly affixed to the rear end of the truck.

The base end of the mast 15 rests on a cradle 24 secured to the mast by bands 26 and pivotally supported on the frame 22 by a transverse pin 28. The mast is adapted to be raised to vertical position by pivoting it about the axis of the transverse pin 28 and our improved mechanism for performing this function will now be described.

A housing 30 is secured to the mast 15 rearwardly of the cradle 24 as by welding at 32. A winch including two drums 34 and 36 on a shaft 38 is carried in the housing. The drums are loose on the shaft and either drum can be connected to the shaft by a clutch 40 therebetween splined to the shaft and adapted to be shifted by a lever 42. The shaft is driven by a worm wheel 44 fixed thereto and having a worm 46 in mesh therewith. The worm shaft is driven by a hydraulic motor 48 carried on the housing.

atent 0 ice Means including a pump 50, pipes 52 and flexible tubing 54 to the motor is provided for supplying fluid flow in opposite directions to the motor for rotating the drums in either direction, the direction of flow through the motor being under the control of a valve 56 operated by a handle 58. A cable 66 is anchored at its ends respectively to the drum 34 and to the lower end of the mast 15 at 62 and extends in a plurality of double reaches 64 over sheaves 66 and 68 carried on the bottom end of the mast and on the frame of the vehicle beneath the pivot 28. It will be apparent that winding of the cable onto the drum 34 will raise the mast about the pivot 28. A screw 70 threaded into the vehicle frame is adapted to cooperate with a yoke 72 integral with the mast and stop the mast when it reaches vertical position. The mast is adapted to be secured in this position by placing a locking pin in registering holes 74 and 75 in the screw and yoke.

A cable 76 is anchored at one end 78 to the bottom end of the inner portion 16 of the mast and extends therefrom to and over a sheave 80 carried on the top end of the outer mast portion 15. From thence the cable extends to and is anchored to the drum 35. It will be apparent that winding of the cable onto the drum will move the inner portion 16 of the mast outwardly of the portion 15 to thus extend the mast. Locking means is provided at 82 for supporting the mast in extended position. A post 84 adjustably threaded into the base end of the mast 15 serves to give firm and additional support to the mast during servicing operations.

It will now be apparent that we have developed and herein disclosed a new and improved mast raising and extending mechanism that is extremely compact and simple and which can perform the required functions with maximum convenience and minimum of time. The carrying of the servicing mechanism on the mast by the housing 30 eliminates the adapting of such mechanism to and the mounting of it onto the truck, thereby providing a unit construction adaptable to mass production at minimum cost.

Having thus disclosed our invention what we claim as new and desire to secure by Letters Patent is- 1. A motorized service unit comprising a frame, a tubular mast pivotally mounted upon and initially supported in horizontal position on the frame and containing an inner telescopic extension section, a single winch mounted on the mast near its base and including two drums arranged for alternate operation under manual control, a cable leading from one drum of the winch to the base of the mast for swinging the mast to a vertical position, and a cable leading from the other drum of the winch to the telescopic section for raising it to its extended position in the mast.

2. A motorized service unit as described in claim 1, further characterized in that the base of the mast is provided with a post adjustable for providing the mast with direct and positive support from beneath when in its upright position.

References Cited in the file of this patent UNITED STATES PATENTS 301,019 Teal June 24, 1884 801,372 Foltz Oct, 10, 1905 994,942 Libbe June 13, 1911 2,627,560 Eitel Feb. 3, 1953 

